L6234

Three-phase motor driver

Datasheet - production data

Description
The L6234 is a triple half bridge to drive a
brushless DC motor.
It is realized in BCDmultipower technology which
combines isolated DMOS power transistors with
1PXFS40 CMOS and bipolar circuits on the same chip.
By using mixed technology it has been possible to
optimize the logic circuitry and the power stage to
achieve the best possible performance.
Features The output DMOS transistors can sustain a very
 Supply voltage from 7 to 52 V high current due to the fact that the DMOS
structure is not affected by the second breakdown
 5 A peak current
effect, the RMS maximum current is practically
 RDSon 0.3  typ. value at 25 °C limited by the dissipation capability of the
 Cross conduction protection package.
 TTL compatible driver All the logic inputs are TTL, CMOS and µP
 Operating frequency up to 150 kHz compatible. Each channel is controlled by two
separate logic inputs.
 Thermal shutdown
The L6234 device is available in a 20-pin
 Intrinsic fast free wheeling diodes
PowerSO20 package.
 Input and enable function for each half bridge
 10 V external reference available Table 1. Device summary
Order code Package Packing

L6234PD PowerSO20 Tube

L6234PD013TR PowerSO20 Tape and reel

March 2017 DocID1107 Rev 11 1/15

This is information on a product in full production. www.st.com
Contents L6234

Contents

1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Pin connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6 Circuit description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

7 Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

8 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1 PowerSO20 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2/15 DocID1107 Rev 11

L6234 Block diagram

1 Block diagram

Figure 1. Block diagram

".W

DocID1107 Rev 11 3/15

15
Pin connections L6234

2 Pin connections

Figure 2. Pin connections

Table 2. Pin functions

Pin no. Name Function

1, 10 Common ground terminal. In the PowerSO package these pins are used to
GND
11, 20 dissipate the heat forward the PCB.

A sense resistor connected to this pin provides feedback for motor current
2 SENSE1
control for the bridges 1 and 2.
3 EN 2
Enable of the channels 1/2/3. A logic LOW level on this pin switches off both
8 EN 1
power DMOS of the related channel.
13 EN 3
4 IN 2 Logic input of channels 1/2/3. A logic HIGH level (when the corresponding EN
7 IN 1 pin is HIGH) switches ON the upper DMOS power transistor, while a logic
14 IN 3 LOW switches ON the corresponding low side power DMOS.

5 OUT 2
6 OUT 1 Output of the channels 1/2/3.
15 OUT 3
9, 12 Vs Power supply voltage.
Internal voltage reference. A capacitor connected from this pin to GND
16 VREF
increases the stability of the power DMOS drive circuit.
17 VCP Bootstrap oscillator. Oscillator output for the external charge pump.
18 VBOOT Overvoltage input to drive the upper DMOS
A sense resistor connected to this pin provides feedback for motor current
19 SENSE2
control for the bridge 3.

4/15 DocID1107 Rev 11

L6234 Thermal data

3 Thermal data

Table 3. Thermal data

Symbol Parameter PowerSO20 Unit

Rth j-case Thermal resistance junction case 1.5 °C/W

DocID1107 Rev 11 5/15

15
Maximum ratings L6234

4 Maximum ratings

Table 4. Absolute maximum ratings

Symbol Parameter Value Unit

VS Power supply voltage 52 V

VIN, VEN Input enable voltage – 0.3 to 7 V
(1)
Ipeak Pulsed output current 5 A
VSENSE Sensing voltage (DC voltage) -1 to 4 V
Vboot Bootstrap peak voltage 62 V
VOD Differential output voltage (between any of the 3 OUT pins) 60 V
fC Commutation frequency 150 kHz
VREF Reference voltage 12 V
Ptot Total power dissipation (TA = 70 °C ) 2.3 W
Tstg, Tj Storage and junction temperature range -40 to 150 °C
1. Pulse width limited only by junction temperature and the transient thermal impedance.

Recommended operating conditions

Table 5. Recommended operating conditions
Symbol Parameter Value Unit

VS Supply voltage 7 to 42 V
VOD Peak to peak differential voltage (between any of the 3 out pins) 52 V
Iout DC output current (TA = 25 °C) 4 A
Sensing voltage (pulsed tw < 300 nsec) -4 to 4 V
VSENSE
Sensing voltage (DC) -1 to 1 V
Tj Junction temperature range -40 to 125 °C

6/15 DocID1107 Rev 11

L6234 Electrical characteristics

5 Electrical characteristics

VS = 42 V; Tj = 25 °C unless otherwise specified.

Table 6. Electrical characteristics

Symbol Parameter Test condition Min. Typ. Max. Unit

VS Supply voltage - 7 - 52 V
Vref Reference voltage - - 10 - V
IS Quiescent supply current - - 6.5 - mA
TS Thermal shutdown - 150 - - °C
TD Dead time protection - - 300 - ns

Output DMOS transistor

IDSS Leakage current - - - 1 mA

RDSon ON resistance - - 0.3 - Ω

Source drain diode

VSD Forward ON voltage ISD = 4 A; EN = LOW - 1.2 - V

TRR Reverse recovery time IF = 4 A - 900 - ns
Tpr Forward recovery time - - 200 - ns

Logic levels

VINL, VENL Input LOW voltage - -0.3 - 0.8 V

VINH, VENH Input HIGH voltage - 2 - 7 V
IINL, IENL Input LOW current VIN, VEN = L - -10 µA
IINH, IENH Input HIGH current VIN, VEN = H - 30 - µA

DocID1107 Rev 11 7/15

15
Circuit description L6234

6 Circuit description

The L6234 is a triple half bridge designed to drive brushless DC motors. Each half bridge
has 2 power DMOS transistors with RDSon = 0.3 .
The 3 half bridges can be controlled independently by means of the 3 inputs IN1, IN2, IN3
and the 3 inputs EN1, EN2, and EN3. An external connection to the 3 common low side
DMOS sources is provided to connect a sensing resistor for the constant current chopping
application.
The driving stage and the logic stage are designed to work from 7 V to 52 V.

8/15 DocID1107 Rev 11

L6234 Typical characteristics

7 Typical characteristics

Figure 3. Quiescent current vs. supply voltage Figure 4. Normalized quiescent current vs.
switching frequency

,T > P $ @ ,T,T#  +]

 
7M ƒ&

7 M  ƒ&
7M ƒ&


7 M  ƒ&

7M  ƒ&
 7 M   ƒ&

 
7 M   ƒ&






 
             
9 V >9 @ IVZ >N+]@

$0Y $0Y

Figure 5. Typical RDSon vs. supply voltage Figure 6. Source drain forward on voltage vs.
junction temperature

5 ' 6 2 1  96 ' >9@

> : @     

  
7 M     ƒ &


 


 
7 M    ƒ & 
 


  7 M  ƒ&

,RXW $
  
,R X W  $

 
                  
9 V >9 @ 7M>ƒ& @

$0Y $0Y

DocID1107 Rev 11 9/15

15
Typical characteristics L6234

Figure 7. Typical diode forward ON Figure 8. Reference voltage vs. supply voltage
characteristics

,6 ' > $ @ 9UHI>9 @

 
7 M  ƒ&




' 0 2 6 2 1  ' 0 2 6 2 ))





7 M  ƒ&




 
          
9 6 ' >9 @ 9 V >9 @
$0Y $0Y

Figure 9. Reference voltage vs. junction Figure 10. PowerSO20 transient thermal
temperature resistance

9 UH I> 9 @

9 V   9

9 V   9


 9 V   9

 9 V   9


           
7 M >ƒ & @

$0Y $0Y

10/15 DocID1107 Rev 11

L6234 Typical characteristics

Figure 11. PowerSO20 thermal resistance Figure 12. PowerSO20 thermal resistance
(mounted on aluminium substrate) (mounted on FR4 monolayer substrate)

$0Y $0Y

Figure 13. PowerSO20: with external heatsink Figure 14. Thermal impedance of PowerSO20
and standard SO20

$0Y $0Y

DocID1107 Rev 11 11/15

15
Package information L6234

8 Package information

In order to meet environmental requirements, ST offers these devices in different grades of

ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK® is an ST trademark.

8.1 PowerSO20 package information

Figure 15. PowerSO20 package outline
1 1 5

D $
F
D
E H '(7$,/%
'(7$,/$ (
H
+ '(7$,/$
OHDG

'
D VOXJ

'(7$,/%

  
*DJH3ODQH
&

6 6($7,1*3/$1(
/
* &
%277209,(: &23/$1$5,7<
( (

(

 

3620(&
'
K[


12/15 DocID1107 Rev 11

L6234 Package information

Table 7. PowerSO20 package mechanical data

Dimensions (mm )
Symbol
Min. Typ. Max.

A - - 3.6
a1 0.1 - 0.3
a2 - - 3.3
a3 0 - 0.1
b 0.4 - 0.53
c 0.23 - 0.32
D(1) 15.8 - 16
D1 9.4 - 9.8
E 13.9 - 14.5
e - 1.27 -
e3 - 11.43 -
(1)
E1 10.9 - 11.1
E2 - - 2.9
E3 5.8 - 6.2
G 0 - 0.1
H 15.5 - 15.9
h - - 1.1
L 0.8 - 1.1
N 8° (typ.)
S 8° (max.)
T - 10 -
1. “D” and “E1” do not include mold flash or protrusions.
- Mold flash or protrusions shall not exceed 0.15 mm (0.006").

DocID1107 Rev 11 13/15

15
Revision history L6234

9 Revision history

Table 8. Document revision history

Date Revision Changes

15-Nov-2011 10 Updated Features in coverpage and Table 4.

Removed PowerDIP 20-pin package and all references throughout
document.
15-Mar-2017 11 Updated Figure 1 on page 3 (replaced by new figure).
Added note 1. below Table 7 on page 13.
Minor modifications throughout document.

14/15 DocID1107 Rev 11

L6234

IMPORTANT NOTICE – PLEASE READ CAREFULLY

STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and
improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on
ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order
acknowledgement.

Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or
the design of Purchasers’ products.

No license, express or implied, to any intellectual property right is granted by ST herein.

Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product.

ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners.

Information in this document supersedes and replaces information previously supplied in any prior versions of this document.

© 2017 STMicroelectronics – All rights reserved

DocID1107 Rev 11 15/15

15